Method and apparatus for loading film into a cassette

ABSTRACT

A method and apparatus for attaching a film to a spool. A cassette shell rotatably contains the spool and the roll of the photo film. Two retaining holes are formed in a trailer of the photo film. A slot is formed in the spool, in an axial direction of the core, receives the trailer, and has a first rigid wall and a second flexible wall. Two retaining hooks are projected from the rigid wall, and are fitted in the respective retaining holes to retain the trailer in the slot. Two preventive ridges are projected from the flexible wall, and avoid disengagement of the retaining holes from the retaining hooks. The trailer is inserted through a passage mouth of the cassette by an insertion device and firmly secured on the core. The flexible wall has a gap, and defines two flap portions such that an original form is recoverable resiliently. The preventive ridges are disposed on the respective flap portions.

This is a divisional of application Ser. No. 08/208,382 filed Mar. 10,1994.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a photo film cassette, and morespecifically to a photo film cassette having a spool on which photo filmcan be secured easily, a method of loading the film and an apparatus forsuch loading.

2. Description of the Related Art

Photo film of the 135 type, contained in a cassette, is the most populartype marketed currently. The 135 photo film cassette has a cassetteshell constituted of a cylindrical body and two end caps. Thecylindrical body is formed of a thin metal plate, with the caps fittedthereon. The cassette has a spool on which photo film is wound in a formof a roll and which is contained in the cassette shell. To assemble thisphoto film cassette, several methods are known. According to the methoddisclosed in U.S. Pat. No. 4,614,019 (corresponding to JP-B 2-691) forexample, the photo film is first wound on the spool. The cassette isthen assembled while covering the photo film within the cassette shellin a darkroom.

U.S. Pat. No. 3,910,516 (corresponding to JP-A 49-107732) and JP-A52-77723 also suggest a photo film cassette producing method. In thismethod, a spool is incorporated into an empty cassette in an illuminatedroom. A tongue-like guide plate is then inserted into a photo filmpassage port formed in the cassette. Then, in a darkroom, a trailer ofphoto film is inserted into the cassette while being guided along theguide plate. The trailer is retained on the spool fixedly. The spool isfinally rotated to wind the photo film up into the cassette.

It is also suggested by U.S. Pat. Nos. 4,834,306 and 4,846,418 and acommonly assigned European patent application published as EP-A2 0 406815 (corresponding to JP-A 3-37645) to construct a photo film cassettein which a cassette shell is constituted of parts formed from resin, androtation of a spool causes a leader of the photo film to exit to theoutside of the cassette. Such a leader-advancing cassette is differentfrom photo film cassettes conventionally in use because the leader ofthe photo film is fully contained within the cassette even beforeexposure and after exposure. The cassette has advantages in that thephoto film is reliably protected from accidental exposure to ambientlight. Also, the lack of external protrusion of the leader facilitateshandling of the cassette.

The assignee of the present application has proposed a photo filmcassette in which a spool has a slot for receiving a trailer of thephoto film. In the slot, retaining hooks are formed. Holes formed in thetrailer are fitted on the hooks. Also, slip-preventive ridges are formedin opposition to the hooks and at positions beside the hooks. The ridgescontact with the trailer, press the trailer against an opposite wall ofthe slot, and retain the trailer inside the slot in cooperation with thehooks. The trailer is thus prevented from disengagement from the slot,and is reliably secured to the spool.

However, it is difficult to insert the trailer into the above-describedspool, mainly due to the arrangement of the hooks and the ridges. Thetops of the hooks extend beyond the opposite tops of the ridges, so thatthe trailer must be bent or curved forcibly before the trailer can befully inserted into the slot between the hooks and ridges. Even when thetrailer is safely inserted, excessive force for the insertion isrequired. In production of this cassette, the above-describedtongue-like guide plate as proposed in U.S. Pat. No. 3,910,516 and JP-A52-77723 could be used for assistance in the insertion of the trailerinto the cassette. However, the guide plate might also be bent or curvedinside the slot during guiding the trailer.

There is an alternative proposal as suggested in a commonly assignedU.S. Pat. No. 5,360,183 (corresponding to JP-A-4-122925). A spooldisclosed therein has a slot for receiving a trailer. In the slot,retaining hooks and slip-preventive ridges are formed. The hooks areretractable from inside the slot. In the course of advancing the trailerinto the slot, the hooks are retracted. When the holes come to thehooks, the hooks are resiliently recovered into the slot, are fittedinto the holes, and retain the trailer. This alternative has problems inthat the trailer cannot have a stable position inside the slot, and haslow reliability in successful engagement with the hooks. Even after theengagement, the hooks can be moved by shock or vibration of thecassette, and the trailer is accidently disengaged from the hooks.

SUMMARY OF THE INVENTION

In view of the foregoing problems, an object of the present invention isto provide a photo film cassette having a spool on which photo film canbe secured easily.

Another object of the present invention is to provide a photo filmcassette having a spool on which photo film can be secured reliably by asimple structure.

In order to achieve the above and other objects and advantages of thisinvention, a photo film cassette includes a spool which has a core,photo film of which a trailer is secured on the core and which is woundon the spool in the form of a roll, and a cassette shell for rotatablycontaining the spool and the roll of the photo film. At least oneretaining hole is formed in the trailer of the photo film. A slot isformed in the spool and extends in an axial direction of the core, andhas first and second walls. At least one retaining claw is projectedfrom the first wall into the slot, and is fitted in the retaining holeto retain the trailer in the slot. At least one preventive projection isprojected from the second wall into the slot to prevent disengagement ofthe retaining hole from the retaining claw. The preventive protection isretractable away from the first wall.

In a preferred embodiment, the second wall has a cutoff. The spoolincludes at least one flap portion defined by the cutoff. An originalform of the flap portion is recoverable resiliently. The preventiveprojection is disposed on the flap portion. When a load of 200 grams isapplied to the preventive projection, the preventive projection isshifted by at least 1 mm.

In the present invention, the photo film can be secured on the spooleasily and reliably, by a simple structure. The trailer will not be bentor curved seriously by the full insertion of the trailer into the slotbetween the hooks and ridges. The trailer can thus be safely insertedwithout excessive force.

In a method of loading the photo film into the cassette, the trailer ispicked up by a pick-up device. The pick-up device is inserted throughthe passage port, to insert the trailer into the cassette shell. Thepick-up device is inserted into the slot, to retract the preventiveprojection away from the first wall to mount the trailer on the spool.The pick-up device is then drawn out of the cassette shell, to allow thepreventive projection to recover its form and extend toward the firstwall, to retain the trailer on the retaining claw. The spool issubsequently rotated to wind the photo film around the spool and intothe cassette shell.

The pick-up device can be a tongue-like guide plate, and is preventedfrom being bent or curved inside the slot in the course of guiding thetrailer. Also, the pickup device aids in the insertion of the trailerinto the cassette.

In the present invention, the trailer is maintained in stable positioninside the slot, and is engaged easily with the hooks. Even after theengagement of the hooks, the hooks cannot be moved by shock or vibrationof the cassette.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and advantages of the present invention will becomemore apparent from the following detailed description when read inconnection with the accompanying drawings, in which:

FIG. 1 is an exploded perspective view illustrating a photo filmcassette of the preferred embodiment of the present invention, togetherwith an opener for opening a shutter;

FIG. 2 is a front elevation illustrating a spool incorporated in thecassette of FIG. 1 and on which a trailer is to be retained;

FIG. 3 is a cross section illustrating the spool;

FIG. 4 is an explanatory view, in cross section partially broken,illustrating a preferred embodiment of the photo film loading apparatusand a cassette to be loaded with the photo film;

FIG. 5 is an explanatory view, in cross section, illustrating the photofilm cassette with an inserter jig of the loading apparatus;

FIG. 6 is an explanatory view, in perspective partially broken,illustrating the spool with the photo film and a spool drivingmechanism; and

FIG. 7 is an explanatory view, in bottom perspective, illustrating apartly flexible core wall of a spool of another preferred embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE PRESENTINVENTION

FIGS. 1 to 3 illustrate a preferred embodiment. A spool 13 is disposedin a cassette shell 10 constituted of a pair of shell halves 11 and 12molded from resin. Pairs of ridges 14 are formed on the inside of theshell halves 11 and 12. When photo film 15 is wound around the spool 13and contained within a spool chamber between the shell halves 11 and 12,the ridges 14 are in contact with the outermost turn of the photo film15 to prevent the roll of the photo film 15 from loosening. When thespool 13 is rotated in a direction to unwind the film 15, namely,clockwise in FIG. 1, the roll of the photo film 15 is rotated clockwisetogether with the spool 13. During rotation of the roll of the photofilm 15, a leading end of the photo film 15 abuts on the separator claw16a, which is formed on shell half 12, to separate the leading end fromthe roll of the film 15.

Port walls 11a and 12a are formed on the shell halves 11 and 12,respectively. With the shell halves 11 and 12 joined together, the portwalls 11a and 12a define a photo film passage port 16. A shutter plate17 is supported by the port walls 11a and 12a. Both ends of the shutter17 are provided with rotary shaft portions 17a to be supported betweenthe port walls 11a and 12a, so that the shutter 17 is rotatable about anaxis parallel to the axis of the spool 13. An end of one of the shaftportions 17a has a key 18, which extends through a face of the cassetteshell 10. When an opener member 19, of a camera or the like, is fittedon the key 18 and rotates the key 18, the shutter 17 is rotated in therange between positions of blocking and opening the passage port 16.

A pair of flanges 21 are formed on the spool 13. The photo film 15 iswound on a core 20 of the spool 13 between the flanges 21. Both ends ofthe spool 13 extend through faces of the cassette shell 10, and areprovided with keys 22. The keys 22 are used for engagement with a drivemember for rotating the spool 13 in a known manner. Each of the keys 22has a notch 22a formed therein.

The core 20 is constituted of core walls 23 and 24, between which a slot25 is formed. As illustrated in FIGS. 2 and 3, a central gap 23c isformed in the core wall 23 to render it flexible, and define twosymmetrical flaps 23a and 23b, which respectively have slip-preventiveridges 26a and 26b formed thereon. The flaps 23a and 23b have aresilient tendency to elastically recover their original form. Theresilient tendency is set so that the ridges 26a and 26b are shifted by1 mm or more when a load of 200 grams is applied thereto, in thedirection away from the rigid core wall 24. Two retaining hooks 27 areformed on the rigid core wall 24 at an interval which is wider than theridges 26a and 26b. The right side of the slot 25, as viewed in FIG. 3,is formed to be an entrance 25a to receive insertion of a trailer 15a ofthe photo film 15 as illustrated in FIG. 1.

The trailer 15a of the photo film 15 as provided has two retaining holes28 formed thereon, which are engaged with the retaining hooks 27. Theridges 26a and 26b press the trailer 15a in the direction opposite toprojecting direction of the retaining hooks 27, so that the holes 28 areprevented from disengagement from the retaining hooks 27, even if aforce for pulling the photo film 15 from the slot 25 is applied to thetrailer 15a. The trailer 15a is further provided with two pick-up holes29 at an interval which is wider than the retaining holes 28. Thepick-up holes 29 are used during an insertion operation of the trailer15a into the slot 25.

FIG. 4 illustrates a preferred embodiment of an apparatus for insertingphoto film 15 into the cassette. The apparatus is adapted to fixing thephoto film 15 on to the spool 13 and winding it thereabout, after thespool 13 and the shutter 17 have been mounted between the shell halves11 and 12. A base 30 is provided with a holder 31 shaped incorrespondence with the outline of the cassette shell 10 for receivingand supporting the cassette shell 10. On the base 30 is journaled alever 32, which is driven by a hydraulic cylinder device or the like(not shown) through a linkage mechanism (not shown). When the cassetteshell 10 is supplied into the holder 31, the lever 32 presses and holdsthe cassette shell 10 in the holder 31.

With the cassette shell 10 pressed by the lever 32, the cassette shell10 is fixedly oriented, by positioning of the port wall 12a on apositioning edge 33, to direct the passage port 16 in a predetermineddirection. Both lateral faces of the base 30 are provided with a pair ofarms 35 journaled thereon with each shaft 35a. The arms 35 are driven bya stepping motor or the like (not shown). The arms 35 are connected witha connecting plate 37, which is used for attacking a clawed inserter jig39 to the arms 35. The inserter jig 39 is arcuate, is formed of flexiblethin metal, and is provided with pick-up claws 39a at its distal endsthereof.

A slide frame 40 is arranged on one lateral face of the base 30 to beslidable toward, and away from, an end face of the cassette shell 10,and is adapted to support a drive unit 41. The drive unit 41 selectivelyrotates the spool 13 and the shutter 17, and includes a fork 41a (seeFIG. 6) for engagement with the key 22 of the spool 13, a motor fordriving the fork 41a, the opener member 19 for engagement with the key18, and a motor for driving the opener 19. The slide frame 40 is in theretracted position before the cassette shell 10 is set in the holder 31,and is moved to the drive position after setting the cassette shell 10in the predetermined orientation. The opener 19 for the shutter 17 andthe fork 41a for the spool 13 are respectively engaged with the keys 18and 22.

As shown in FIG. 4, the spool end is provided with the key 22 an thenotch 22a. Note that, as discussed above, the opposite spool end is alsoprovided with a key 22 and a notch 22a. The inside face of the base 30in opposition to the drive unit 41 is provided with a sensor as (notshown), such as a photo sensor which detects the position of the notch22a in the spool 13, so as to check the rotational position of the spool13 with reference to the predetermined orientation for positioning theslot 25.

A feeder 45 of the photo film 15 is arranged to face the base 30. Thefeeder 45 is connected to a device for supplying the photo film 15. Eachtime one strip of photo film 15 is cut off and contained into thecassette shell, the feeder 45 holds a trailer 15a in position forstandby. When the trailer 15a is protruded from the feeder 45, the holes29 are positioned in a predetermined positional relationship withrespect to the pick-up claws 39a.

FIG. 5 illustrates relative positions of the cassette shell 10 and thearm 35 while the cassette shell 10 is positioned by the holder 31 andthe edge 33. The shaft 35a is substantially equally distant from theslot 25 in the core 12a, the passage port 16, and the new claw 39a. Whenthe arm 35 is rotated counterclockwise from the standby position of FIG.5, the claw 39a is passed through the passage port 16 and is eventuallybrought into the slot 25 within the core 12a.

The operation of the inserting the photo film 15 into the cassette shell10 is described below. The cassette shell 10 is assembled with the newspool 3 in an illuminated room, i.e., not in a darkroom. The emptycassette therefore can be assembled reliably and easily, together withthe shutter 17 and other separate parts, such as an indicator member forunexposed and exposed states, and a regulating member for rotation ofthe spool. The cassette shells 11 and 12 are secured together firmly byultrasonic welding, hook engagements, or other known methods.

The empty cassette thus assembled is brought into a darkroom, and setinto the photo film loading apparatus illustrated in FIG. 4. To set theempty cassette, the lever 32 is in the open position. The slide frame 40is retracted. With the cassette shell 10 is set in the holder 31, thelever 32 is swung to the pressing position to hold the cassette shell 10on the holder 31 and the edge 33 in the predetermined orientation. Theslide frame 40 is next moved to the drive position where the fork 41a isengaged with the key 22 and the opener 19 is engaged with the key 18.

When the opener 19 and the fork 41a are firmly engaged with therespective keys 18 and 22, the drive unit 41 is actuated to drive thespool 13 in the winding direction, namely counterclockwise in FIG. 4.The sensor inside the base 30 monitors the position of the notch 22a atthe key 22 and, when the notch 22a has come to the predeterminedposition, sends a stop signal to the drive unit 41. The spool 13 isstopped to direct the entrance 25a of the slot 25 toward the passageport 16. Note that it is possible to regulate the rotational orientationof the spool 13 beforehand during the transportation of the emptycassette into the holder 31. In such a case, the sensor can be omittedfrom the base 30.

The opener 19 is driven by the drive unit 41 to rotate the shutter 17 toopen the passage port 16. The stepping motor is then energized to drivethe arm 35 to rotate through a predetermined angle. The inserter jig 39rotates together with the arm 35, to engage the pick-up claws 39a withthe holes 29 in the trailer 15a of the photo film 15. Further rotationof the arm 35 causes the pick-up claws 39a to pick up the trailer 15aand pull the photo film 15 from the feeder 45. The pick-up claws 39awith the trailer 15a are inserted through the passage port 16, and theninto the slot 25 between the core walls 23 and 24. In the course ofinsertion of the pick-up claws 39a, the trailer 15a is forced into thespace between the flexible core wall 23 and the tops of the retaininghooks 27.

The core wall 23 consists of the two flexible separate flaps 23a and 23bas described above. The ridges 26a and 26b shift 1 mm or more under aload of 200 grams. Therefore the ridges 26a and 26b are pressed by thetrailer 15a advancing into the slot 25, until the flexible flaps 23a and23b are flexed away from the rigid core wall 24. The pick-up claws 39a,during the insertion, never receive any resistance of the ridges 26a and26b. It is thus possible with ease to advance the trailer 15a fully intothe slot 25. Were it not for the gap 23c, both core walls would be rigidand would provide excessive resistance to the trailer 15a. With the gap23c imparting flexibility to the core wall 23, the trailer 15a is notgreatly deformed even when in contact with the ridges 26a and 26b. Whenthe retaining holes 28 reach the retaining hooks 27, the hooks 27 arefitted in the holes 28. The ridges 26a and 26b then recover theiroriginal positions resiliently, and press the trailer 15a toward therigid core wall 24. It follows that the retaining hooks 27 retain theretaining holes 28 firmly without risk of disengagement.

With the trailer 15a retained on the core 20 of the spool 13, the arm 35rotates back to the standby position, while pulling the pick-up claws39a out of the cassette shell 10. The retaining hooks 27 are shaped tokeep the photo film 15 from moving in the direction toward the passageport 16. Once the holes 28 are retained on the retaining hooks 27, theholes 28 will not become disengaged from the slot 25 when the inserterjig 39 is pulled out of the slot 25. It is noted that, to remove theinserter jig 39 from the cassette, it is possible to rotate the spool 13counterclockwise first, until the inserter jig 39 is removed from theslot 25. The arm 35 can then be rotated clockwise to pull the inserterjig 39 out of the cassette shell 10. This alternative operation ispossible due to the flexible thin characteristic of the inserter jig 39.

After the arm 35 is brought back to the standby position, the fork 41aof the drive unit 41 is driven to rotate the spool 13 in thecounterclockwise direction. The photo film 15 is thus wound up aroundthe core 20 of the spool 13. The photo film 15 is further drawn out ofthe feeder 45 by tension due to rotation of the spool 13, while beingwound into the cassette shell 10. When a predetermined length of thephoto film 15 is passed through the feeder 45, the spool 13 is stoppedfrom rotating. A cutter incorporated in the supply device of the photofilm is actuated to cut the photo film 15. A rear end of the photo film15 in the course of being wound is cut out by the cutter into the shapeof the leader, at the same time as a front end of next strip of photofilm is cut out by the cutter into the shape of the trailer, in whichthe holes 28 and 29 are further punched.

After the strip of the photo film 15 is cut off, the spool 13 is drivento wind up the photo film 15 entirely into the cassette shell 10. Uponwinding the leader of the photo film 15 into the cassette shell 10, thespool 13 is stopped. The opener 19 is rotated clockwise, to move theshutter 17 to the blocking position to close the passage port 16. Inthis state, the inside of the cassette shell 10 is shielded completelyfrom ambient light. The lever 32 is retracted to the releasing position.The cassette shell 10 with the photo film 15 contained is removed fromthe holder 31, for which another empty cassette is supplied. Theoperation of loading a cassette with photo film 15 is repeatedsimilarly.

The operation of the apparatus can be controlled in a known manner by amicroprocessor based controller or the like. Also, known devices can beused for sensing and driving the various members. Finally, one skilledin the art will readily be able to select the form and material of thespool to attain the critical strength thereof in light of the disclosureherein.

FIG. 7 partially illustrates a core 80 of another preferred spool, inwhich a partly flexible core wall 80a is used in combination with theformer rigid core wall 24. A channel-shaped cutout 83 is formed in thecore wall 80a to define a flexibly resilient flap 82. Twoslip-preventive ridges 81a and 81b are formed on the flexible flap 82proximate entrance 25a.

Although the present invention has been fully described by way of thepreferred embodiments thereof with reference to the accompanyingdrawings, various changes and modifications will be apparent to thosehaving skill in this field without departing from the scope of thepresent invention as defined by the appended claims.

What is claimed is:
 1. A method of loading photo film into a cassette,said cassette including a spool, and a cassette shell provided with aspool chamber for containing said spool rotatably and a photo filmpassage port extending from said chamber to an outside of said cassetteshell, at least one retaining hole being formed in a trailer of saidphoto film, said spool includes, a slot extended in an axial directionof a core of said spool, for receiving said trailer, said slot beingdefined by first and second walls, at least one retaining clawprojecting from said first wall into said slot for being fitted in saidretaining hole to retain said trailer in said slot, said methodcomprising the steps of:forming at least one preventive projection onsaid second wall to project into said slot for preventing disengagementof said retaining hole from said retaining claw, said preventiveprojection being retractable away from said first wall said second wallbeing defined by a cantilever portion; picking up said trailer withpick-up means; first inserting said pick-up means through said passageport, to insert said trailer into said cassette shell; second insertingsaid pick-up means into said slot, to retract said preventive projectionaway from said first wall, and to mount said trailer on said spool byengaging said retaining hole on said retaining claw; drawing saidpick-up means out of said cassette shell, to allow said preventiveprojection to recover its original position to retain said retaininghole on said retaining claw; rotating said spool to wind said photo filmaround said spool, so as to wind said photo film up into said cassetteshell.
 2. A photo film loading method as defined in claim 1, wherein atleast one pick-up hole is formed in said trailer, and picked up by saidpick-up means.
 3. A photo film loading method as defined in claim 2,wherein said pick-up means is arcuate and moves rotationally about arotational center of an arcuate arrangement of said pick-up means, andsaid trailer is picked up in course of said rotational movement of saidpick-up means.
 4. A photo film loading method as defined in claim 3,wherein said trailer is fed during said first inserting step.
 5. A photofilm loading method as defined in claim 4, wherein said trailer is sodirected as to cross an arcuate path of a said pick-up means.
 6. Asystem for loading photo film into a cassette, said system comprisingphoto film having at least one retaining hole formed in a trailerthereof, and a cassette including a spool, and a cassette shell providedwith a spool chamber for containing said spool rotatably and a photofilm passage port extending from said chamber to an outside of saidcassette shell, said cassette comprising,a slot formed in said spool andextended in an axial direction of a core of said spool, for receivingsaid trailer, said slot being defined by first and second walls; atleast one retaining claw formed on said first wall to project into saidslot for being fitted in said retaining hole to retain said trailer insaid slot; and at least one preventive projection formed on said secondwall to project into said slot for preventing disengagement of saidretaining hole from said retaining claw, said preventive projectionbeing retractable away from said first wall, said second wall beingdefined by a cantilever portion, said, system further comprising aloading apparatus which comprises: holder means for holding saidcassette shell in a predetermined orientation to position said passageport in a predetermined direction; an inserter member for inserting saidtrailer into said cassette shell, said inserter member being movablebetween an inserted position where said inserter member is passedthrough said passage port and into said slot and a home position wheresaid inserter member is exited from said passage port; a pick-up endportion disposed on said inserter member for picking up said trailer,and when said inserter member moves to said inserted position, saidpick-up end portion is inserted in said slot, to mount said trailer onsaid spool while retracting said preventive projection away from saidfirst wall, and when said pick-up end portion is drawn out of said slot,said preventive projection recovers toward said first wall to retainsaid trailer on said retaining claw; and spool drive means for rotatingsaid spool to wind said photo film around said spool.
 7. A photo filmloading system as defined in claim 6, wherein a shutter is mounted insaid passage port for preventing ambient light from entering said spoolchamber, said shutter being displaceable between closed and openpositions, and when in said closed position, said shutter blocks saidpassage port to prevent ambient light from entering said chamber, andwhen in said open position, said shutter opens said passage port toallow passage of said photo film, said apparatus furthercomprising:shutter drive means for driving said shutter to displace saidshutter to said open position while said cassette is held by said holdermeans.